This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Our program for automated tilt series acquisition, SerialEM, has continued to allow rapid data acquisition and effective use of our Tecnai microscopes. Efforts in the past year included the following developments. 1) The handling of data from 16-bit cameras and from 4-port readout cameras was improved after we obtained such a camera for our F20. 2) Remaining problems with montaging were worked out when Johanna Hoog from the EMBL used montaging extensively. 3) A relatively low-dose procedure was implemented for realigning the zero-loss peak when using an energy filter. The procedure is run automatically at a set interval during a tilt series and eliminates the need for operator intervention. 4) Installation procedures and instructions were improved, so that it is now easier to provide an initial package to new users and to provide and install program updates. SerialEM is now being used on at least three Tecnais in other laboratories (a T12 at the Burnham Institute, approximately 250/hours in 12 months;a TF20 at Scripps Research Institute, approximately 60 GB in 11 months;and a new TF30 at the University of Queensland, approximately 250 hours and approximately 90 GB of data in 7 months). Several other laboratories have either installed the program or obtained packages for it. SerialEM has been ported to run on a JEOL 3100 microscope by Tobin Fricke at the Lawrence Berkeley National Laboratories, and after some effort it now appears to run satisfactorily. Several laboratories with comparable microscopes would like to run the program, and JEOL USA, Inc. is interested in facilitating this process. An informal arrangement has been worked out whereby Jaap Brink from JEOL will help users to install the program and provide a first contact for training and assistance. A manuscript on SerialEM has been submitted for publication.